I have been characterizing changes in markers for Nitric Oxide Synthase in the rat tooth following pulp exposure. Specifically, I have prepared the mesial surface of the maxillary right first molar, and have reacted sections for NADPH-diaphorase, inducible nitric oxide synthase iNOS), and neuronal NOS (nNOS) immunoreactivity. In addition, I have evaluated the effect of sympathectomy on these changes. I plan on further characterizing changes that occur in the tooth pulp following insult and evaluating other related neural changes.